In a machine, such as a motor grader, for example, an engine and a transmission work together to propel the machine and operate implements. A motor grader may have over a dozen hydraulic implements under an operator's control which makes the operators job one that makes full use of the hands. An automatic transmission reduces the demands on the operator, but an automatic transmission alone may not provide significant relief where the operator must frequently change gears or speeds to accomplish a particular task. Also, an automatic transmission may be less efficient. For some tasks, the operator desires to maintain manual transmission control. Accordingly, it will be appreciated that it will be highly desirable to have an electronically controlled transmission which automatically shifts gears, yet which, by simple operator control, switches from an automatic mode to a manual mode.